1. Field of the Invention
The invention pertains to a piston-cylinder unit, especially a pneumatic spring, with a cylindrical pressure tube, in which a piston is guided with freedom of axial movement. The piston has a piston rod at least at one end, which is guided to the outside through an opening in a wall, which closes off the end of the pressure tube, and the pressure tube is surrounded by a heat-shrink sleeve, which extends more-or-less radially inward at the exit end of the piston rod and has a pass-through opening through which the piston rod projects.
2. Description of the Related Art
In a piston-cylinder unit of this type, it is known that the pressure tube can be covered by a shrink-fit plastic sleeve, the heat-shrink sleeve covering the outside surfaces of the pressure tube where the end has been flanged over toward the inside. Moisture can be drawn into the gap between the pressure tube and the heat-shrink sleeve where the gap is open to the outside; this moisture causes corrosion on the outside surface of the pressure tube, which is disadvantageous.